1. Field of the Invention
Embodiments of this invention relate generally to the transport of objects between various manufacturing process steps, and in particular embodiments to methods for hydrodynamically loading and unloading objects into and out of substantially touchless hydrodynamic transport systems, and systems incorporating the same.
2. Description of Related Art
Modem manufacturing methods often require a number of processing steps to be performed on an object to transform or prepare the object into a finished product. Even after the object has been fabricated, cleaning steps may be required to remove residue and contaminants such as particulates, organics, and inorganics collected during processing. For example, in conventional magnetic recording media processing techniques a slurry is applied to texture the surface of the magnetic media. This slurry must subsequently be removed, often by mechanically scrubbing the magnetic recording media using polyvinyl alcohol (PVA) rollers. Several cleaning steps may be required, because magnetic recording media often requires particle removal efficiencies as small as 0.3 microns, and inorganic/organic particulate levels as low as 1.times.10.sup.10 atoms/cm.sup.2.
Careful handling is essential as these fragile objects are transported between process steps. Conventional techniques employed for transporting delicate objects such as semiconductor wafers and magnetic recording media between process stations may require both mechanical and human intervention. Once the object completes a processing step, it is loaded into a transportation cassette, carried by process operators to the next processing station, and unloaded from the cassette. This intervention increases the chance of damage to, and contamination of, the objects.
Human intervention and manual transportation between processing steps in a multi-step cleaning system can be eliminated by employing substantially touchless hydrodynamic transport chutes to transport objects from one process module to another. One example of substantially touchless hydrodynamic transport chutes is disclosed in U.S. patent application Ser. No. 09/196,856. Each substantially touchless hydrodynamic transport chute includes a transfer slot formed between two walls. Formed in the walls and directed into the transfer slot are support nozzles angled towards the output side of the transfer slot for creating fluid flow and fluid bearings in the transfer slot and urging objects through the transfer slot. In addition, induction nozzles are formed in the walls near the input side of the transfer slot for inducing objects into the input side of the transfer slot. A base supports the first and second walls and is grooved in substantial alignment with the transfer slot for receiving and bottom-centering objects in the transfer slot.
However, even if an processing system with hydrodynamic transport chutes between process modules is employed, manual loading and unloading of objects into and out of such systems is still required. In addition, because hydrodynamic transport chutes may transport only one object at a time, the manual and repetitive loading and unloading of single objects into and out of such automated processing systems increases the chance of frictional wear and damage to the object as it comes into contact with the cassettes and human hands, and increases the chance of breakage of the object due to dropping or other mishandling. Contaminants may also be introduced during the loading and unloading process. Manual loading and unloading techniques also may be slower due to the lack of automation and required human intervention, and may be costlier due to the employment of process operators. In addition, no process steps may be carried out during the loading and unloading process.